Firecracker



J. B. DECKER April 21, 1931.

FIRECRACKER Filed OCT.. 27, 1928 Qnven/(oz. WW

Patented Apr. 21, 1931 UNITED STATES i JOSEF B. DECKER, OF ELKTN, MARYLAND FIRECRACKER Application led October 27, 1928. Serial No. 315,460.

`This invention relates to pyrotechnic devices and more particularly to a container for explosive compounds for use in Vsuch devices andto a method of making the same.

It is a general object ofthe present invention to provide a novel and improved container for kexplosive compounds for pyrotechnic devices and a novel method of forming the same. y Particularly, itis an object of the invention to provide a novel method of folding and forming a sheet of suitable material about a, charge of explosive compound to form a substantially cylindrical packet containing said compound `and being of suhcient strength to provide such resistance as to cause aloud report when the compound is ignited.

' jA feature of the invention consists in theV provision of an explosive container formed ofalternately interleaved convolutions of a fibrous material containing between alternate convolutions a. charge of explosive material. y AV further feature of the invention comprises acontainer for explosive material contiedlabout a fuse extending into the pocket.

` A still further feature of the invention consists in the provision of an explosive container formed for the most part of a cylinder 'rolled from a double thickness of fibrous material but'being completed by a single thickness of material adhesively secured around the outer surface thereof and integral with the main portion of the material.V ArrThe present invention is 'illustrated by way of fexample only in connection with the explosivecontainer for a fire'cracker and will be readily understood by reference to the accompanying drawing and following specification. .i It is to be understood that the form shown is exemplary only andV that such changes may be made therein as'fall within the scopeV of the attached claims. j' In said'r drawing:

" Figure 1 is a plan view of a sheet of material with a charge of explosive and fuse rest ing theredn g1 Figure 2il1ustrates the first step xin forming the explosivecontainer i Figure 3 illustrates the next step Figure 4 illustrates the rolled-up cylinder with the tab having adhesive applied thereto; A` Figure 5 is a perspective showing the completed explosive container; and Y Figure 6 is a longitudinal section through a fire cracker provided with an explosive container constructed according to the present invention@V In the manufactureof various pyrotechnics and particularly certain types of lire crackers or'salutes, it has been found desirable to place E ance against disruption at the time of explol sion to increase the noise. A lire cracker constructed in accordance with this general custom is shown in Fig. 6, wherevthe tube 10 lis usually formed of a series of convolutions of paper with adhesive between the convolutions. Within the tubel isa bag or container 11 holding explosive material and having projecting from one end a fuse 20 which sticks out beyond the end of the tube 10. The present invention provides a novel explosive container and method of making the same.

Referring to Fig. 1, it willbe seen `that the main portion of the container 11 is asheet of suitable brous material, such as kraft paper,

which is quite flexible and yet strong.` In this n figure, the paper is indicated by the reference character 13 and is of generally rectangular shape with the reentrant corner 14. The dotted lines on the paper indicate areas 'into which it can be considered to be dividedfor A A the purposes of the present description. On this basis the sheet may be considered to comprise a main rectangle defined by the lines 15 and 16 and the two outer edges of the sheet` and having a side tab 17 of rectangular form and an end tab 18 of similar shape. A suitable chargeof explosive material 24, such as, for instance, a mixture. of potassium perchlorate, sulphur and aluminium powder, is placed as indicated `on la sectionofthe area 195 Then a fuse 20 Vof anywelllknwn type is CTI arranged with one end buried Iin the pile of explosive material, which is granular or powthe right of the fuse and explosive is turned over the explosive along the line indicated at 22 in Fig. l. tion of the pocket wall on each sideof theexplosive, and the fuse will be confined.

The next step consists in rolling the sheet and its contained powder in the` direction of the arrow in Fig. 3, forming it into as tight a cylinder as possible. During this operation, it will be evident that a certa-in amount of explosive will be forced longitudinally along the pocket and beneath the folded portion indicated by the reference character 23v in Fig. 3, so that when the container assumes the form indicated in Fig. 4, it'will be seen to 'consist of an elongated pocket having explosive 'distributed throughout a considerable portion yof its length with the Vpocket rolled into a cylinder of several convolutions. Another way of looking at it is that it comprises alternateinterleaved convolutions of two lengths, i. e., the tab 17 and the main rectangle with an explosive between adjacent convolutions. Y

When' the condition shown in Fig. 1 'has been reached, the tab 18 of a single thickness of paperf alone remains, and this is either at the time or previously coated with a suitable adhesive. Continued rolling causes this tab to adhesively secure itself about the cylinder and hold thesame in its rolled-up position against the unrolling tendency due kto the resilience of the paper. Y The next operation consists in 'wrapping and tying al thread kor a small string' 25 about the end of the Vcylinder close to the fuse. This will tie down and close the end 4of the pocket into a .neck to engagextightly abo-ut the fuse and prevent the escape of gases around the fuse during explosion and at the same time serve to retain the fuse in position. It' Will be *noted that this neck portion which is crimped in about the fuse is formed only by that part` of the paper'which extends beyond the turned-up edge 24 ofthe tab 17, and hence has only about one-half as lmuch paper in it as the remaining portion of the cylinder, so that it can be readily compressed by the string 25. The finisheddi'ameter of the cylinder is such that it can readily be placed within a tube such as 10 and either retained,

in there by its friction or secured by an ap,- plication ofsuitable adhesive. y y 1 Now there will'be a long por- The resulting container for explosive material produced by the method just described is very simple to make and produces an extremely compact package of an explosive material which is suficiently strong to resist the expanding of the gases upon explosion so as to cause a loud report. The feature of providing two tabs of the rectangle, one to be folded over the explosive and one to be provided with adhesive, are considered to be important featuresof the invention. Furthermore, the feature of having a reduced number of layers of paper at theend of the cylinder where it is secured about the fuse is of extreme importance, since it simplifies the operation of tyingand insures a tighter-joint between the fuse and thewalls of the envelope or bag for-the explosive. Y

Having thus described the invention, What is claimed as new and desired to, be secured by Letters Patent iszA e 1. The method ofl making a fire-cracker comprising forming a sheet of VAfibrous mai terial of rectangular form with Va reentrant corner, placing explosive on a portion offsaid sheet, folding one of the tabs formed by said cut-out corner over said explosive, folding a portion of the doubled .sheet over saidex- Y plosive and then rolling the sheetand explo-A sive into a cylinder.V A i comprisingforming a sheet of fibrous material of rectangular'form with a reentrant cor ner, placingY explosive on a portion of said sheet, folding one of the tabs formed bysaid cut-out corner over said explosive, foldinga portion of the doubled sheet over saidexpl sive, rolling the folded sheet intoa cylinder, gummingrthe remaining tab-and rolling 'it about said cylinder. v

3. The method of making a fire-cracker comprising forming a sheet of fibrous material into a, rectanglehaving a side and anend tab each smaller than-the rectangle, placing a charge of explosive material on a portion ofjsaidrectangle, folding said side tab over said explosive,'rolling said doubled portion of material and explosive and adhesivelysecuring said end tab thereabout. f y

4. A fireecracker formed of interleaved, alternateiconvolutions of fibrous material secured togethery at one. edge to form-a spiral pocket, explosive'inl said pocket,ra fuse entering said pocket an'dmeans to secure theends of one set of said convolutions about said fuse. f- Y 5. A fire-cracker formed of interleavedalternate sets of convolutions of "brousf'material secured together at one edge to form a c, ,n 95, 2. The method of making a lirelcracker 6. A lire-cracker formed of interleaved, a1- ternate sets of convolutions of brous material secured together at one edge to form a spiral pocket, means closing one end of said pocket, explosive in said pocket, a fuse entering said pocket, and a group of adjacent convolutions adhesvely secured around the interleaved eonvolutons.

In testimony whereof I hereunto afix my signature.

JOSEF B. DECKER. 

